The purpose of this study is to examine the diagnostic validity of the leukocyte esterase and nitrite tests in the point-of-care detection of catheter-associated urinary tract infection in hospitalized older adults. It is estimated that 40% of all hospitalized patients will acquire some type of nosocomial infection, and catheter-associated urinary tract infection (CAUTI) is the most common. According to a recent report by the Centers for Disease Control and Prevention, approximately 32% of acute care patients will develop a CAUTI. Besides limiting the use of urinary catheters, there is currently very little evidence to support preventitive interventions for this condition in the hospitalized older adult population. Before novel interventions can be tested for efficacy, researchers must first understand the diagnostic validity of available CAUTI measures, including the rapid, inexpensive, and commonly utilized leukocyte esterase and nitrite tests. Research indicates that older adults, particularly those with chronic diseases, may be unable to mount an effective immune response against pathogens. This phenomenon, termed "immunosenescence," has the potential to restrict the white blood cell response to urinary pathogens, reflected by a "negative" leukocyte esterase test. Alternatively, an active, acute infection elsewhere in the body, which is likely in the hospital setting, may elevate the white blood cell response, leading to a "positive" leukocyte esterase test in the hospitalized older adult population. It is not known what "net effect" these two phenomena have on the overall diagnostic validity of the leukocyte esterase test in this population, but the proposed study will inform this area of inquiry. Furthermore, research indicates that a reduced concentration of urinary bacteria in the quantitative urine culture, the diagnostic "gold standard" for UTI, should be used in patients with urinary catheters. This reduced concentration of 1,000 (rather than 100,000) organisms per milliliter of urine will be the "gold standard" against which the leukocyte esterase and nitrite tests will be compared in the proposed study. The three aims for this cross-sectional study are to: 1) Determine the sensitivity, specificity, and positive predictive value of the leukocyte esterase test to detect CAUTI in hospitalized older adults; 2) Determine the sensitivity, specificity, and positive predictive value of the nitrite test to detect CAUTI in hospitalized older adults, and; 3) Examine the diagnostic validity of the combined leukocyte esterase and nitrite tests to detect CAUTI in hospitalized older adults. This research has the potential to eliminate the delay in CAUTI identification and treatment in hospitalized elders, which may prevent the complications associated with high bacterial-load CAUTI, such as pyelonephritis, septic shock, and death. [unreadable] [unreadable] [unreadable]